<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>

<form onsubmit="return false">
    <textarea name="message" id=""  style="height: 300px;width: 300px">

    </textarea>
    <input type="button" value="发送消息" onclick="send(this.form.message.value)">

    <textarea id="responseText"  style="height: 300px;width: 300px">

    </textarea>
    <input type="button" value="清空内容" onclick="document.getElementById('responseText').value=''">
</form>

<script>
    var socket;
    if (window.WebSocket){
        socket = new WebSocket("ws://localhost:7000/hello")
        //收到服务器端回送的消息
        socket.onmessage = function (ev) {
            var rt = document.getElementById('responseText');
            rt.value=rt.value + "\n" +ev.data
        }
        //连接开启
        socket.onopen =function (ev) {
            var rt = document.getElementById('responseText');
            rt.value= "连接开启了...."
        }

        //连接关闭
        socket.onclose =function (ev) {
            var rt = document.getElementById('responseText');
            rt.value.append("\n连接关闭了..." )
        }
    }else {
        alert("当前浏览器不支持websocket")
    }

    //发送消息到服务器
    function send(message) {
        //判断websocket是否创建好了
        if (!window.socket){
            return
        }
        if (socket.readyState == WebSocket.OPEN){
            socket.send(message)
        } else {
            alert("连接没有开启")
        }
    }
</script>

</body>
</html>